


Making Math Fun

by AceOnIce



Series: Kinktober 2020 [4]
Category: Shadowhunters (TV)
Genre: Academic Smut, Alternate Universe - College/University, Anal Sex, Bottom Magnus Bane, Dom/sub Undertones, M/M, Math Kink, Mathematics, Orgasm Control, Orgasm Delay/Denial, Sex Toys, Teasing, Top Alec Lightwood, Tutoring, kind of
Language: English
Status: Completed
Published: 2020-10-06
Updated: 2020-10-06
Packaged: 2021-03-07 16:07:34
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,526
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26870383
Author URL: https://archiveofourown.org/users/AceOnIce/pseuds/AceOnIce
Summary: Alec helps Magnus with his math homework, but it's a lot kinkier than it sounds.
Relationships: Magnus Bane/Alec Lightwood
Series: Kinktober 2020 [4]
Series URL: https://archiveofourown.org/series/1946230
Comments: 25
Kudos: 179





	Making Math Fun

**Author's Note:**

  * For [SomeSleepySloth](https://archiveofourown.org/users/SomeSleepySloth/gifts).



> Kinktober Day 6  
> Written for the whump prompts:  
> Please  
> “Get It Out”/ No More/ “Stop, Please”
> 
> (I'm also surprised how tame this one turned out with those prompts!)

Magnus has always hated math with a passion. He hates it now more than ever as it’s the only thing standing between him and an orgasm at the hands of his very capable boyfriend. 

Magnus is sitting at the desk in his room, a vibrating buttplug pressed against his prostate, trying to finish his math homework. He only has one question left, but he’s aching to come, his cock hard and straining against his pants, a wet stain having soaked through to the front of the material. Alec sits in the chair beside him, watching silently, a hand on Magnus’ knee. It’s a simple touch, but it’s their only place of contact and Magnus finds it hard to focus on anything but the warmth of Alec’s palm through the fabric of his jeans and his own sharp arousal. Alec’s intense gaze doesn’t do anything to calm him.

“Come on Magnus,” Alec coaxes in a smooth voice that drips of sex, “You haven’t even started number thirty.”

Magnus turns to glare at his boyfriend, adjusting in the chair, attempting to get some form of relief- be it more friction or less stimulation against his prostate. The toy seems to stay where it’s lodged in him no matter how he shifts. “I can’t focus.”

Alec’s answering smile holds no sympathy. “You’re almost done, you can concentrate a little longer.”

“Easy for you to say,” Magnus mutters. He’s barely pressed the pencil to the paper when the vibrations shut off. He’s half-relieved for the small break, but it’s a whine that falls from his lips. Alec’s hand leaves his knee, running down the length of his back instead, soothing him. 

“Solve this correctly and I’ll turn it back on.” Alec leans closer to speak the words lowly, right into Magnus’ ear, licking at the outer shell. 

Magnus groans, attempting to focus on the numbers on the page when all he wants is to grab his boyfriend, throw him onto the bed, and _finally_ do something about the hard on he’s been sporting for the better part of the last hour. All because of Alec and his attempts at ‘helping’ Magnus pass his class. Magnus has no idea how he managed to land Alec, an econs major and an A+ student, as his boyfriend, but it’s been the best relationship of his life. Even if Alec insists on torturing him, in an absolutely delicious way, under the guise of tutoring him.

Magnus begins simplifying the equation, expanding the terms in the bracket _._ He doesn’t even finish writing down his second term before Alec is clicking his tongue and reaching over to point out his mistake. “You squared them individually, but they’re in the parenthesis so you have to multiply these two terms by…? _”_

Magnus groans and this time it has nothing to do with his arousal. Alec is right about the expansion, of course he is, but that doubles the amount of work Magnus has to put into this problem and he just wants to be done with this homework. 

“By what?” Magnus asks, erasing the error he’d made.

“I’m sure you can remember it,” Alec says, leaning back in his chair and pulling out his phone. 

Magnus glares, considering giving the whole thing up and just climbing onto Alec’s lap and riding him right there- except then he wouldn’t get his homework done and submission of any incomplete work is an automatic F. 

He flips through the notes to his left, finding the example that he needs _,_ and sets to work applying it to this problem. He can feel Alec’s eyes on him, but his boyfriend doesn’t say anything which means he hasn’t made another mistake- yet. 

He multiplies the two terms by themselves and remembers to multiply them by two- a detail Alec had helped him learn by putting a cock ring on him and eating him out until he memorized it. The memory makes him shiver and he doublechecks that he hasn’t made any stupid mistakes- a liklihood considering how distracted he is- before glancing up at Alec for confirmation. Alec is watching him with a small smile that makes Magnus melt a little before he leans in and licks into Magnus’ mouth without any preamble.

Magnus eagerly returns the kiss, dropping his pencil to curl his hand in Alec’s hair, his free hand slipping under Alec’s shirt. He feels the buttplug surge back to life and moans into the kiss. Alec drags it out, but when Magnus tries to shift from his seat to Alec’s lap, his boyfriend pulls away, lips wet and red and so utterly enticing. 

“Finish the question,” Alec reminds him, eyes trailing over Magnus’ body, likely taking in his disheveled state. 

Magnus releases Alec’s hair, reaching down to press a hand to his erection. Alec catches his wrist before he can, giving Magnus a warning glare. “Finish the assignment.”

Magnus grumbles but reluctantly turns to the last step of the problem. He rolls his hips experimentally, biting his lip to hold in a groan when the pleasure shoots through him as the plug vibrates against his prostate. He shifts against it, cock rubbing against his underwear for a hint of friction. He thinks he can get off like this if he can just-

Alec taps the paper impatiently. “Don’t you dare come yet.”

“Fuck,” Magnus groans, pressing his pencil to the paper, forcing himself to sit still. “I’m almost done, I think I deserve an orgasm.”

“I’ll tell you when you deserve an orgasm. You haven’t earned it yet. Come on, just solve the equation so I can give you your reward.”

Magnus is desperate to come, with Alec’s permission because it’s always so much better that way, so he forces himself to concentrate. He can’t sit still with the toy buzzing inside him so his leg jumps up and down under the table. He tries to remember the steps to solving for X now that he’s expanded the brackets, to no avail.

He looks to Alec, meeting expectant hazel eyes. “What formula do I use here?”

Alec must be growing impatient- or he’s taking pity on Magnus because he tells Magnus the equation rather than making him search for it himself. Magnus jots it down and starts solving. He makes several small mistakes- earning disapproving noises from Alec- before he finally finds the solution. 

Magnus drops his pencil, turning to face Alec, “There- can I please come now?”

Alec purses his lips, clearly considering. What he’s considering Magnus has no idea- he’s finished the assignment!

“You had to look up how to expand the square and you didn’t know the quadratic formula for the last question. Plus you made a lot of careless mistakes.”

Magnus whines, shooting up and out of his chair so he can pulls his shirt off and toss it to the side. He’s done with math. “No more,” he says simply, moving his homework to the side before undoing his pants and pushing the material down, freeing his cock and revealing the buttplug that’s still vibrating in his ass. “Get it out and fuck me- please.”

“Only since you asked so nicely,” Alec says, sounding a bit breathless as he positions himself behind Magnus, turning off the toy and pulling it out with a slick pop.

Magnus groans, feeling almost painfully empty as Alec checks that he's still decently stretched and lubed. “Please Alec, fuck me.”

“I’ve got you baby,” Alec promises, pressing a palm to Magnus’ back, rubbing circles on Magnus’ spine with his thumb. He moves slowly as he slides his cock into Magnus’ ass, but Magnus is done with slow, is done with waiting. He moves his hips back, taking Alec in as deep as he can, until he’s utterly filled with Alec’s perfect cock. 

Magnus reaches to stroke himself, but Alec’s hand beats him there, long, calloused fingers wrapping around his leaking length. Magnus bucks into it, already on a knife’s edge. When Alec draws out and thrusts back in, Magnus moans and he knows he would have come if Alec had suddenly tightened his grip, keeping Magnus’ orgasm at bay. 

Magnus whines at the loss, shaking around Alec. He feels like crying, nails scraping the desk that he’s bent over. His voice sounds wrecked, desperate, when he cries out, “Why?”

“Tell me the quadratic formula and you can come,” Alec tells him through panted breaths, pressing kisses to his neck. 

Magnus wants to cry, wants to punch Alec, wants to fight. But more than that, _he wants to come._ He holds tight to the desk as Alec continues thrusting into him, hitting his prostate without fail, hand wrapped tightly around Magnus’ dick.

Magnus frantically searches his memory for the formula Alec had just told him for his homework. He lets out a sound that’s half-cheer, half-sob when he realizes he knows this. “X equals negative b, plus minus square root of b-squared minus four ac over two a! _”_

Alec’s grip loosens as he kisses Magnus’ temple. “Good boy.” 

That’s all it takes for Magnus to come so hard he almost blacks out. He decides there are definitely worse ways to learn math.

**Author's Note:**

> All the thanks to [SomeSleepySloth](https://archiveofourown.org/users/SomeSleepySloth/pseuds/SomeSleepySloth).  
> for helping me with math terms and puns and inspiring this. Enjoy just one of her many math-Malec jokes:  
> "Magnus: Alec, I have a new name for my dick. I shall call it maths. Because it is hard as fuck"


End file.
